4th Aug 1938, 19 Sqn RAF, are the first operational unit to receive the Supermarine Spitfire.

These early Mk.1's had a two blade prop, a flattened canopy and lacked the range of refinements that would be introduced both before and after WW2 began.

But they were the first of the many, some which would be flown by the 'few' in 1940.

That famous statement by Churchill, Never, in the field of human conflict, would so many be owed by so few, in fact came after a visit, at the height of the Battle of Britain, to the command centre at RAF Uxbridge, in West London. He was mesmerised by what he saw there, at a bad time during the battle.
On the way back to Central London, he told his military attache, don't talk to me, I am so moved. Then he uttered that famous phrase, later used in a speech.
I visited the preserved command centre at Uxbridge 2 years ago, it is fascinating and moving, even now.

Supermarine's masterpiece was of course, not the only RAF monoplane entering service then, but it was the one that was demonstrably as good, in many ways better, than what the soon to be opposition was building.
And it looked the part too.